Draft-regulating system



Dec; 10, 1929. H. c. SCHMIDT 1,739,375

DRAFT REGULATING SYSTEM Original Filed Nov. 12, 1926 M i i silg ,f z K /,I 375121221; 61/

Eh 5' T 66* 44 (lumen x1701 A (267mm Q fiakmzcii 66 I Patented Dec. 10, 1929 PATET OFFICE HERMAN C. SCHMIDT, 9F RICHMOND, VIRGINIA DRAFT-REGULATING- SYSTEM Application filed November 12, 1926, Serial No. 14S,018; Renewed May 16, 1329.

My invention relates to draft regulating systems of the type wherein a liquid damper is employed at the outlet end of a flue or stack for controlling the draft therethrough,

regulation of the draft being efi'ected by varying the level of the liquid constituting the damper with respect to the outlet end of the flue or stack, and my purpose, generally speaking, is to provide, in such a system,

1 means of a novel nature for indicating, at a point remote from the damper, at or near the furnace or oven for example from which the flue or stack leads, the level of the liquid constituting said damper for the information of an attendant in properly regulating the draft. 7

More particularly it is my purpose to provide means for the purpose mentioned in the form of a combination air and liquid'gauge device which is simple in construction, cheap and easy to produce and install, accurate, reliable, unlikely to getiout of order, and which includes means for readily and easily ridding same of possible obstruct-ions without aifecting its accuracy and without danger of injury to any part thereof.

My inventive idea is capable of embodiment in different mechanical structures, one

of which is shown in the accompanying drawings. I desire to have it understood, however, that the structure shown is intended merely as a disclosure of the essential features and novel characteristics of my invention in one preferred form and that its scope is as defined in the appended claim.

In the drawings, wherein like characters of reference denote corresponding parts in the different views Fig. 1 is an elevation, partly in section, showing more or less conventionally a draft regulating system of the liquid damper type embodying the novel and essential features of my invention;

Fig. 2, a central vertical section through the gauge device of my invention; and

Fig. 3, a rear View, partly in section, of said gauge device.

A draft regulating system of the type in which my improvements are adapted to be embodied may take varying mechanical forms, the only essential being that it include a liquid body so located with respect to the outlet end of the fine or stack constituting part of the system as to be capable, by varying the level thereof, of controlling the draft a; through said flue or stack. Such a system is illustrated more or less conventionally in the present instance and is observed to include a flue or stack lO'leading from a furnace or oven 12 and having its outlet end 14 Ci) directed downwardly and opening into a receptacle 16 in which is contained a body of water 18 the level of which may be raised to completely seal the outlet end of said fine or stack, or lowered to restrict the efiective discharge area at the outlet end of said flue or stack to any desired extent.

As the furnace or oven 12 ordinarily is located in the cellar or basement of a building, or on a lower floor thereof, and as the outlet end of the flue or stack 10 and the receptacle l6 ordinarily are located on or above the roof of the building, and as it is desirable that an attendant at the furnace or oven 12 be enabled to regulate the draft through the fine or stack 10, a pipe 20 is led from said receptacle to a point in the vicinity of the furnace or oven where it is placed in communication with water inlet and outlet pipes 22, 24, respectively, equipped, respectively, with valves 26, 8 28, whereby water may be supplied to or discharged from said receptacle to vary the level of the water 18 therein in a manner which is apparent.

Since, as aforesaid, the level of the water in receptacle 16 controls the draft through flue or stack 10, and since it is desirable that an attendant at the furnace or oven should be cognizant at all times of the level of the water in said receptacle, so that he may properly operate the valves 26, 28 to secure and maintain a desired level of water in said receptacle, I have provided a gauge device of novel form for indicating accurately at a point in the vicinity of the furnace or oven 12 and the valves 26, 28 the level of water in said receptacle. This gauge device includes essentially an air bell 30 formed either as an integral part of receptacle 16 or as an element seperate therefrom and secured therein in any desired manner, in either event being closed at its upper end and open at its lower end and so arranged within the receptacle as to constitute a pressure chamber wherein air is trapped and held at a pressure dependent upon the level of the liquid 18 within said receptacle.

A conduit 32 is connected to the upper end of air bell and leads to a valve 34 mounted in this instance on the back of the panel 36 of a gauge 38 located for convenience adjacent to valves 26, 28.

lhe panel 36 of gauge 38 carries a liquid receptacle 40 on the rear face thereof at its lower end, and a transparent tube 42 is connected at its lower end with said receptacle 40 near the bottom thereof and extends upwardly along the front of said panel, the latter being suitably calibrated as at 44 adjacent to said tube.

, Valve 34 consists of a casing 46 and a plug 48 rotatable therein, said casing being provided with three ports 50, 52 and 54 equi-- distantly spaced circumferentially thereof and having connected therewith, respectively, the conduit 32, a conduit 56 leading to any suitable source of compressed air, and a conduit 58 leading to and opening into the top of receptacle 40. Plug 48, on the other hand, is provided with a duct 60 having its ends opening through the side of the plug at points spaced circumferentially thereof the same distance apart as any two of the ports 50,

52, 54 whereby, in one rotated position of the plug, communication is established between the conduits 32, 58', and conduit 56 is blanked, as shown in 3 of the drawings, and in another rotated position of said plug, communication is established between conduits 32, 56, and conduit 58 is blanked, this latter position being secured by rotating the plug in the direction of arrow a from the position shown in Fig. 3.

Formed in casing 46 is an atmospherically opening vent aperture 62 so positioned that one end or the other of duct 60 will aline therewith during rotation of plug 48 from the position last mentioned to the position shown in Fig. 3, so that any compressed air held entrapped within duct 60 during rotation of the plug from the position last mentioned to the position of Fig. 3 will be permitted to escape from said duct before it establishes communication between the conduits 32, 58.

When the plug 48 of valve 34 is in the position shown in Fig. 3 establishing communication between the'conduits 32, 58 it is evident that the air pressure in receptacle 40 is the same as the air pressure in air bell 30, and since the level of the liquid in tube 42 is dependent on the air pressure in receptacle 40, which pressure is caused by the height of the water in receptacle 16, it is evident that variations in the level of the water in receptacle 16 and hence the distance between the outlet end 14 of the flue or stack 10 and th surface of the water 18 will beindicated by the level of the liquid in gauge tube 42.

Should the conduit 32 become obstructed the plug 48 of valve 34 is rotated to place said conduit in communication with conduit 56 whereby compressed air is admitted to the conduit 32 to force the obstruction therefrom, and since the conduit- 58 is blanked during the operation it is evident that the air content of receptacle 40 will not be disturbed nor will the gauge be harmed by the admission of compressed air to the system. On return of the plug 48 to its normal posiion shown in Fig. 3 one end of the duct 60 alines with the aperture 62, so that any compressedair entrapped within said duct and which might affect the accuracy of the gauge if allowed to expand within the conducts 32, 58, is vented to the atmosphere before communication is reestablished between conduits 32, 58.

Qbviously a valve of any other suitable type which will serve the purposes of valve 34 asset forth in tne foregoing may be used in lieu of the valve 34 as specifically shown.

From the foregoing description considered in connection with the accompanying draw ings it is believedthat the construction, operation and advantages, of my invention will be apparent. It is desired to point out, however, that various changes and desirable additions may be made in and to the structural arrangement shown within the spirit and scope of my invention as defined in the appended claim.

I claim: 7

In a draft regulating system, a liquid receptacle in which a downwardly directed outlet end of a flue is adapted to be positioned, and a housing formed on the inner face of the sidewall of the receptacle, said housing having its upper end closed and its lower end opened and the side wall of the receptacle having an opening therethrough communicating with the upper end of the interior of the housing whereby a liquid level gauge may be connected with said interior of the housing.

In testimony whereof I hereunto affiX my signature.

HERMAN C. SCHMIDT. 

